545P - Completion of pembrolizumab in advanced non-small cell lung cancer: Real-world outcomes after two years of therapy (COPILOT)

Background

Immune checkpoint inhibitors (ICI) are standard of care in advanced non-small cell lung cancer (NSCLC) without driver mutations. A small proportion of patients (pts) treated with ICIs will achieve durable responses. We describe outcomes of a real-world cohort of pts who completed two years of pembrolizumab (pembro).

Methods

Clinical data of pts who completed 35 cycles of first-line pembro for NSCLC (or 30-34 cycles with reason for cessation other than progression) was collected retrospectively from sites across Australia via the AUstralian Registry and biObank of thoRacic cAncers (AURORA). Primary endpoints were progression rate post pembro completion and progression free survival (PFS). Local treatment of oligoprogressive disease during pembro was included. Analyses were performed using R.

Results

71 pts from six centres with a median age of 66.0 yrs, 49% male & 90% ECOG≤1 were identified. Pts were Caucasian (82%) or Asian (16%); past (69%) or current (25%) smokers with a mean 37 pack year history. Histology comprised 73% adenocarcinoma, 16% squamous. 18 pts (25%) had brain mets at diagnosis, 16 treated (8 resected, 8 RT). Median PD-L1 tumour proportion score (TPS) was 68%; 12 pts (17%) PD-L1 negative, 43 pts (61%) TPS≥50%. No pts had ALK/ROS/EGFR mutations; 29/49 tested (60%) had K-Ras mutations. Median follow up from pembro start was 38.7 months (24.5 – 65.6). Table: 545P

Conclusions

Pts completing two years of pembro for NSCLC in Australia had high rates of K-Ras mutation and PD-L1 expression; a significant proportion had brain metastases and treated oligoprogression. Progression rate post pembro was higher in PD-L1-negative pts and in those without complete response.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

AURORA (AUstralian Registry and biObank of thoRacic cAncers) national database. Each participating hospital in various sites throughout Australia had ethics approval to contribute to the AURORA database via their local ethics committee.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.